Who cares, that book isn't hurting me. Books like those are only for people that already believe that stuff. Just more fluff for them.
There are an awful lot of people within the United States that believe that this is the absolute, uncompromising truth. They then take that belief with them to the polls at election time. Which in turn determines how education gets funded, and how science is taught.
The problem with creationism is it's no more or less valid than any other culture's creation myth. They all made sense at the time they were thought up to the people who imagined them.
Christians believe the earth is 6000 years old. This literal account came from Martin Luther. IIRC, medieval monks had come to this conclusion by counting back the ages of characters in the bible to determine the rough age. The Bible doesn't explicitly give a number. This was only a best guess. Both Augustine of Hippo and Thomas Aquinas asserted that the creation story was an allegory not to be taken literally.
For most people living in the early 16th century, it made sense. Writing didn't really evolve until the 4th millennium. Any history prior to that would have been oral. Which of course gets corrupted over time. Modern archaeology, biology, geology, and astronomy had yet to be invented. So there was no way to prove the 6000 year figure wasn't true.
It was the best answer European society had at the time. Then as science evolved, holes began to appear in the creation myth. Human fossils and artifacts were found that were much older than 6000 years. Then they began finding animal and plant fossils that were millions of years old. Then Darwin came up with his theory of evolution studying the changes in these animals. Then we began finding stars that were more than 6000 light years away from us. Then we discovered the cosmic background radiation and came to the conclusion that the universe is 13.8 billion years. That's the best information we have now.
We're still not sure what caused the Big Bang. Maybe it was divine intervention. We lack the tools to know for sure. However, any Christian who continues to view the Bible creation story as being literal with so much evidence against it is a damn fool. Even the founders of their own church said it wasn't. For most of Christian history it wasn't. This is only a recent invention.